Telegraph converter system and apparatus



June 23, 1953 L. M. POTTS 2,643,291

TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 18, 1947 10 Sheets-Sheet l qlllwqq FIG. I

INVENTOR LOUIS M. POTTS, DECEASED MARTHA w.'c. POTTS, ExEcuTR|x BY ZLVM ATTORNEY June 23, 1953 v 1. M. POTTS 2,643,291

TELEGRAPH CONVERTER SYSTEM'AND APPARATUS INYENTOR LOUIS M. POTTS, DECEASED MARTHA w. c. POTTS, EXECUTRIX BY m ATTORNEY June 23, 1953 L. M. POTTS 2,543,291

TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 18, 1947 10 Sheets-Sheet 5 FIG.4

FIG. 3

INVENTOR LOUIS M. POTTS, DECEASED MARTHA W.C. POTTS, EXECUTRIX BY '7 MM 2 ATTORNEY L. M. PoTTs TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 18, 1947 June 23, 1953 10 Sheets-Sheet 4 INVENTOR LOUIS M. POTTS,DECEASED MARTHA W O POTTS,EXEGUTR|X UNATTORNEY June 23, 1953 L. M. POTTS 2,643,291

TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 18, 1947 10 Sheets-Sheet 5 i LOUIS M.POTTS,oEcEAsl-:D

I MARTHA w.c.PoTTs,sx|-:cuTR|x BOI 296 298 BY 227mm RNEY June 23, 1953 L. M. POTTS 2,643,291

TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 18, 1947 4 l0 Sheets-Sheet 6 FIG. I3 236 I NVIENTOR LOUIS M. POTTS,DECEASEID BY MARTHA w. c. POTTS,EXECUTR|X 271 1 L5 ATTORNEY 270 FIG. I4

June 23, 1953 M. POTTS 2,643,291

TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 18, 1947 10 Sheets-Sheet '7 srovswrl2345$5l2345$ l26-l I I26-2 SLEEVE 12| ROTATION 0F SLEEVE Isl SLEEVE MI ZOI SLEEVE I42 SLEEVE I95 'INVENTOR LOUIS M. POTTS, DECEASED MARTHA w. c. POTTS,EXECUTR|X ATTORNEY June 23, 1953 L. M. POTTS 2,643,291

TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 18, 1947 10 Sheets-Sheet 8 LOUIS M. POTTS,DEGEASED MARTHA w. c. POTTS,EXECUTRIX ATTORNEY June 23, 1953 M. POTTS 2,643,291

TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 18, 1947 10 Sheets-Sheet 9 LOUIS M. POTTS,DECEASED MARTHA w. c. POTTS,EXECUTR|X ORNEY June 23, \1953 L. M. POTTS 2,643,291

TELEGRAPH CONVERTER SYSTEM AND APPARATUS Original Filed June 1a, 1947 10 Sheets-Sheet 10 INVENTOR ATTORNEY Patented June 23, 1953 UNITED STATES PATENT OFFICE TELEGRAPH CONVERTER SYSTEM AND APPARATUS Louis M. Potts, deceased, late of Evanston, 111., by Martha W. C. Potts, executrix, Evanston, 111., assignor to Teletype Corporation, Chicago, Ill., a corporation of Delaware 8 Claims. 1

This invention relates to telegraph converter systems and apparatus wherein signal code com-- binations of one code are converted into signal code combinations of another code and subsequently reconverted into the original signal code combinations.

This application is a division of copending application Serial No. 755,445, filed June 18, 1947, now Patent No. 2,579,612, Dec. 25, 1951.

An object of the invention is to provide a mechanical converter unit for converting five unit start-stop signals into seven unit radio signals.

Another object of the invention is to provide a mechanical converter unit for reconverting. seven unit radio signals into fivev unit start-stop signals.

An additional object of the invention is to provide a motor unit for driving both converter units mentioned above.

Further objects and advantages of the invention will appear as the invention is described nals are received by a radio receiver and reconverted into the original five. unit start-stop signals to accordingly operate conventional telegraph recording apparatus. Use of the seven unit radio code with its error detecting feature has proved valuable where transmission of coded messages is required. For example, when coded messages are transmitted in a form such as ABZ, such a group of letters may stand for a phrase, or even a complete sentence containing several words and receipt of a single incorrect character may render a message unintelligible or give to the message a meaning difierent than was intended. Each code combination in the seven unit radio code change contains three marking and four spacing impulses. Any deviation in this fixed ratio of the number of marking impulses to the number of spacing impulses causes the printing of an error indication character. A misselection indicator used for such a purpose is shown in the United States patent of L. M. Potts, e

No. 2,304,120 dated December 8, 1942. As will become apparent later in the description, in the present invention receipt of an all spacing signal by the five unit start-stop recorder causes the recording of an error indication character.

The present invention contemplates the use of three basic mechanical apparatus units, a motor unit, a five to seven unit code conversion unit, and a seven to five unit code conversion unit. The motor unit is used for driving both converter units or a series of such units. The motor unit in addition to driving the converter unit also drives two sets of cams which may control various cam operated contacts according to the particular system in which the motor unit is used. Also included in the motor unit are several phasing and orienting devices which will be taken up later in the description.

The five to seven unit code conversion unit includes a single magnet selector which sets up the positions of a series of five unit code bars. The setting of the five unit code bars selects one of a plurality of character bars which establishes a selection for a series of seven unit code bars. The selection of the seven unit code bars is in turn transferred to a series of seven gooseneck transmitting levers. Idle signals are automatically inserted to compensate for the gain of a seven unit transmitting cam sleeve, which continuously rotates, over a five unit start-stop selector sleeve. It should be mentioned at this time that in the seven unit radio system the idle signal contains marking impulses for the second, fifth and seventh elements of the code combination.

The seven to five unit conversion unit also includes a single magnet selector which sets up the positions of a series of seven unit code bars. The setting of the seven unit code bars selects one of a plurality of character bars, which establishes a selection for a series of five unit code bars. The setting of the five unit code bars is in turn transferred to a series of five gooseneck transmitting levers. When seven unit idle signals are received, the start-stop apparatus is not released so that no character will be printed by the five unit startstop recorder at this time. If no regular message character or no idle signal character is received, it is an indication that the ratio of three marking impulses to four spacing impulses in the code combination has not been maintained. At this time, the gooseneck transmitting levers will function to send an all spacing signal to the five unit start-stop recording apparatus and in response to the receipt of such a code combination an error indication will be recorded.

A more comprehensive understanding of the invention may be had by reference to the following detailed description when read in conjunction with the drawings wherein:

Fig. l is a plan view of the motor unit;

Fig. 2 is a partial end view of the motor unit;

Fig. 3 is a detailed view of a portionof the motor unit particularly illustrating a cam sleeve orienting device;

Fig. 4 is a detailed view of a portion of the motor unit showing a finder mechanism;

Fig. 5 is a detailed view of a cam operated contact device used in the motor unit for synchronizing purposes;

Fig. 6 is a plan view of the five to seven unit code conversion unit;

Fig. '7 is a detailed view of a portion of a mechanism used for transmitting idle signals in the five to seven unit code conversion unit;

Fig. 8 is an enlarged detailed perspective view, partly exploded, of a mechanism used for delaying certain functional operations while idle signals are being transmitted;

Fig. 9 is a partial end view of the five to seven unit code conversion unit;

Fig. 10 is a detailed view of a part of the idle signal transmitting mechanism;

Fig. 11 is a detailed view, particularly illustrating the single magnet selector utilized in the five to seven unit conversion unit;

Fig. 12 is a detailed view of the character bar bail;

Fig. 13 is a detailed view of the five to seven unit conversion unit, particularly illustrating the mechanism used for storing and transferring seven unit code signals;

Fig. 14 is a detailed View of the latching levers used for the seven unit transmitting levers and the idle signal transmitting levers;

Fig. 15 is a timing diagram of the operation of the five to seven unit code converter unit;

Fig. 16 is a plan view of the seven to five unit code converter unit;

Fig. 17 is a detailed view of the single magnet selector used with the seven to five unit code converter unit;

Fig. 18 is a partial detailed end view of the seven to five unit converter unit;

Fig. 19 is a detailed view of a finder mecha nism used with the seven to five unit code converter unit;

Fig. 20 is a detailed view of the character bar operating bail of the same unit;

Fig. 21 is a partial detailed view of the mechanism utilized in the same unit for transmitting reconverted five unit start-stop signals;

Fig. 22 is a detailed view of a clutch operat ing mechanism used in the seven to five unit code converter unit.

With particular reference to Figs. 1 to 5, inclusive, the motor unit contemplated by the present invention will first be described. Numeral l i represents the base of the unit, upon which is mounted a motor I2 which imparts rotary movement to shaft is and a gear l4 fixedly carried thereby. Gear I4 is in mesh with a gear l6 supported upon a huh I? which is mounted about a shaft [8 for relative movement with respect thereto. By means of an escapement mechanism lg (to be later described), gear l6 drives the shaft 18 which is suitably journaled on the vertically extending supports 2| and 22. Fast to shaft I8 are the gears 23 which are in mesh with gears 2%, for the purpose of driving identical cam assemblies 26 as will later be described.

Carried on the hub H which supports gear [6 is a cam 21 which by means of pin and slot connections 28 supports a slidable escapement member 29. A spring 3|, attached at 32 to cam 2'! and at 33 to escapement member 29, normally urges the escapement member in a downward direction as viewed in Fig. 4. Escapement member 29 is provided with a beveled camming projection 34 and with a driving projection 36 which engages the teeth of a ratchet 3i fixed to shaft I8 by means of a collar 38. Below shaft :3 is positioned a finder magnet 39 which controls armature 4| pivoted by means of lugs 42 on a fixed shaft 43. Armature 4| includes an upwardly extending arm 44 having beveled surfaces Miami 61. A spring 48 normally urges armature 4| in a clockwise direction as viewed in Fig. l.

In accomplishing a finding operation a key 49 is depressed while incoming idle signals are being received. If marking impulses are not received for the second, fifth and seventh impulses as will later be described in connection with the system operations, a relay 5! will be energized and a circuit will be completed through attracted contact tongue 52 for relay 53 which will lock up through its contact tongue 54 and contact pair 56. As contact tongue 57 is attracted, finder magnet 39 is energized and armature 4| moves counterclockwise. Cam 2? is provided with a groove 58, and as this groove presents itself to beveled projection ll of arm 44 of armature ll, the armature is free to pivot counterclockwise, and as it does so, beveled projection 46 carried by arm 44 engages beveled projection 34 of escapement member 29, camming the escapement member to the left as viewed in Fig. 4. As the escapement member snaps back to its original position on its continued rotation, driving projec tion 36 of the escapement mechanism will engage the next succeeding tooth of ratchet 31 so that a change in the driving relationship between gear I6 and shaft 58 has now taken place. In other words, ratchet 37 has slipped back one tooth with respect to escapement member 29. As the armature 4i pivots counterclockwise as just explained above, its insulated tail 59 opens the contact pair 56 to break the locking circuit for relay 53. As long as the apparatus is out of phase with incoming idle signals, relay 5! will become energized and the ratchet 37 will slip back a tooth with respect to escapement member 29 in each rotation of gear Hi. This presumes that the key 49 will be held down until a point will be reached whereat relay 5! will no longer energize and a circuit cannot be completed through contact tongue 52 for the operation of relay 53. This indicates that the idle signals are being properly received and that the apparatus has been brought into phase with remotely located apparatus. The operation of the escapement mechanism l9 will be better understood when the system descriptions are later considered. The circuit shown in Fig. 4 is provided only for the purpose of illustrating the mechanical aspects of the operation of the escapement mechanism.

Fixedly secured to shaft i8 is a cam 6| whose periphery is pursued by a follower 62 which is pivoted at 63. The number of lobes on the cam 6| may vary with the system in which the apparatus is used so that insulated tail 64 carried by the follower 62 may operate contact blade 66 back and forth between contact blades 61 and 68 a fixed number of times in each revolution of shaft l8. lhe contact blades 66, 61, and 68 are associated with a tuning fork phasing arrangement, the details of which will be described hereinafter in connection with the systems.

Returning now to the cam assemblies 26, a descriptionof an orienting mechanism associated with each of said assemblies will be described. Cams 69 control contact pairs H at one side of each cam assembly while cams 12 control contact pairs I3. located at the opposite side of each cam assembly. Contact pairs l i 73 are described here for the purpose of illustration but it will be understood that different numerals will be assigned to the contact pairs shown in the system descriptions as will later appear. Gear 24 is fixed to a slidable shaft 74 mounted within a cam sleeve 84 and a sleeve 85 which are journaled on ball bearings I5 and I6. A coiled spring 71 urges the shaft H to the left as viewed in Fig. 3 by pressing against the interior of gear 25.

Leftward movement of shaft 14 is adjustably restricted by means of a lever I8 pivoted at 79. For adjusting the position of shaft I4 a cup shaped dial member 8| is provided which is threaded upon the annular member 82 and the rim 83 of which bears against lever 78. Thus, by turning the dial member iii the position of shaft I4 will be adjusted and the relationship between the spiral driving gear 23 and the spiral driven gear 24 may be varied, Projecting through the cluster of cams 59, I2, which incidentally are supported on cam sleeve 84, is a dowel pin 86 which also projects through a collar 87 fixed to shaft '14. Thus, dowel pin 36 acts as a driving connection to rotate the cam assembly 26. Annular member 82 is provided with a pointer 88 for use in conjunction with the graduations 83 inscribed on the dial member 8i. Although the specific uses of the motor unit will be described later, it is now apparent that by operation of key 49 the apparatus may be brought into phase with distant apparatus. The orienting mechanism may adjust the apparatus so as to centralize the operation of contact pairs ll, I3 with incoming signals.

With particular reference to Figs. 6 to 15, a description will now be given of the conversion unit which converts five unit start-stop signals into seven unit continuous signals. Numeral IfiI represents a base plate which supports a front wall I02 and a rear wall I83. Suitably mounted on walls I62, M3 b means of bearings HM, I06 is a shaft Iili. A second shaft I08 extends between walls IEE, I03 and is mounted on the bearings I09, III. Transverse to shafts I91, Ills there is supported on bearings IIZ, MS a continuously iii) rotating shaft I I 4 which is suitably coupled to I shaft I8 of the previously described motor unit. Carried by shaft H is a gear lit which is in mesh with a gear II"! fast to shaft Isl. Also carried by shaft us is a gear IIB which is in mesh with gear I Hi fast to shaft 508. Thus, by the above described gearing arrangements continuous rotary motion is imparted to shafts I61, I08. For contributing to the clarity of the description, shaft Iii! may be identified as the five unit shaft while shaft I08 may be called the seven unit shaft.

At the front end of shaft I0! is carried a receiver cam sleeve I2! operable under the control of a single magnet selector mechanism I22 in a manner well known in the art. Such a single magnet selector is shown in the United States patent of Zenner No. 1,937,376, dated November 28, 1933. Each time a start impulse is received by selector magnet I23, stop arm I24 carried by sleeve IZI is freed for rotation as clutch members I and H become effective, and cams I26-I to I2I5-5 sequentially set five swords I27 in either a marking or spacing position according to received signals. Cam I28 is an armature assist cam which assists the operation of armature i253 of selector magnet I 23, while cam I32 is a locking cam which operates locking lever I33. The function of cams I28, I32 form no novel part of the present invention and reference should be had to the Zenner patent for a more complete description of these operations. As the swords I27 are set their pointed ends press against either surface i34 or I35 of associated transfer levers I37 which are pivoted at I38 and have their ends nested in notches of associated slidable code bars IBQ-I to Hid-5.

Also mounted on shaft It? are cam sleeves I GI and M2 which are independently released for a single revolution as will be later described. Discs I43, I it, and i 8 are driving clutch members which are carried by the shaft ill'I. Discs I47 and I48 are carried by cam sleeve MI while discs M9 and I5i are carried by cam sleeve I 42. The clutch members are provided with the usual felt washer I52, I53, I55, and 555. The entire assemblage just described is spring pressed towards the front of the apparatus by a coiled spring Il-ai nested in a hollow portion I58 of gear II'I. This, of course, is for the purpose of providing the necessary gripping pressure for the clutch members.

On selector sleeve 12! is secured a cam I 59, the periphery of which is pursued by follower I6! of clutch throwout lever I62 which is suitably pivoted in the apparatus. Clutch throwout lever includes a stop arm I53 which is bent over at I54 to engage lug I66 formed as part of disc Iii? secured to earn sleeve IGI. Near the end of a revolution of cam sleeve I2I, followor iiii of clutch throwout lever IE2 is lifted outwardly by cam I 55, freeing stop arm I63 from the path of lug I55 of disc I21 and enabling sleeve I-II to rotate for a single revolution. After sleeve I I! is released, cam I523 places throwout lever I62 in its first described position to stop sleeve I4! after it has completed a revolution, Thus, the cycle continues as long as sleeve I2I is rotated. It is understood that sleeve i2I also operates in a start-stop manner for each of its rotations.

Sleeve M2 may be released for a single revolution in two differen manners as will now be described. Pivotally mounted on fixed shaft IE8 is an inverted *ohfilifid lever its having a follower IlI which rides upon a cam I'I2 carried by sleeve Hi5 and an arm IE3 which includes a stop shoulder I'i-i which is in the path of a bent over lug I'iii of stop disc Ill which is suitably fastened to cam. sleeve 5 #12. Also pivotally mounted on shaft IE6 is an inverted U-shaped lever I78 having a follower arm iii": which rides upon cam MI and an arm I32 provided with a lug I33. A third lever IS-i is also mounted on shaft I68 and, includes a depending arm E86 which has formed thereon a stop shoulder I87. It will be noted thatlug of lever H3 is bent to a position. it crosses the arm of lever I84. Stop shoulder il of lever its as shown is in blocking engagement with lug H6 of stop disc Il'r'. As ilzl operates follower arm I'll, stop shoulder iiimovcs out of the path of lug I16 and sleeve M2 is to move a very slight distance until lug iii? abuts against stop shoulder I8? of lever 5%. Cam ii now operates against lever Ild which by means of its lug I83 pushes against arm 2536' of lever and stop shoulder I8? moved out of path of lug HS and sleeve M32 is free to complete its single revolution until again stopped by shoulder Il i of lever 7 I69. It is thus seen that the successive action of cams Il2, I8I may rel-ease sleeve I42.

Sleeve 32 may also be released in a second manner which will now be described. Pivotally mounted on shaft IE3 is a lever I88 which includes a depending arm I90 having bent over lug portion I89 which also crosses arm I86 of lever ISA. Fastened at I8I to lever I88 is a link bar I92 which at its other end is secured at I93 to a lever I94 which is pivoted at I96 and by means of a follower portion I9'I rides upon the cam I98 carried upon sleeve I95 mounted on shaft IE8. Thus, as the low part of cam I98 engages follower I91 of lever Hi l, a spring I99 functions to shift link bar I92 in a direction toward shaft I07, lug I89 of lever IE8 is moved against arm I86 of lever ass and stop shoulder I8! is moved out of the path of lug I'I6 of stop disc Ill carried by sleeve Hit. It is, therefore, now apparent that if cam I'I2 has functioned to operate lever I69 to remove stop shoulder I'I also from the path of lug' I'IB of stop disc I'II, sleeve I42 is free to rotate providing follower portion IQ? of lever Iild is riding the low part of cam I98. The purpose of this arrangement will appear as the automatic insertion of idle signals is later described.

Returning now to the slidable to ltdthe description of the mechanism for converting the five unit signals into seven unit signals will now be resumed. Mounted on sleeve R12 are function cams 'ZIII, 262, 2533, and 2M. Pivotally mounted on rod I68 is a large substantially U-shaped bail 2% which includes a follower projection 291' designed to ride upon the cam 202 under impetus of spring 298. As the high part of cam 202 presents itself to projection 20? the lower portion of bail 2536 pushes the individual projections 209 of seven code bars 2i I-I to ZII-l' moving all code bars to the right as viewed in Fig. 13 against the influence of their individual springs 2 I 2.

Pivotally mounted at 2E3 is a lever 2H5 which is provided with a follower arm 2 I 8 engaging cam 203, and an arm ZI'I to which is pivotally connected at 220 a stripper bail 2I8. Also pivotally associated with stripper bail 2I8 at El is a lever 2I9 which is pivoted at 22! for the purpose of maintaining bail 2 I8 parallel when it is operated. Beneath the stripper 258 are pivotally mounted on rod 222 a series of character bars 223 which also underlie five unit code bars I39-I to I39-5 and seven unit code bars 2II-I to 2II-l. Now as stripper bail 2I8 is operated as follower arm 2M3 of lever ZI I is operated by the high part of cam 2133 against the tension of spring 224 all character bars 223 are pushed downwardly against the action of individual springs 225 and immediately thereafter the high part of cam 2&2 moves all code bars Ell-I to 2i I-? to the right as explained above. While the bars 2II-I to 2i I-'I are still held, follower arm 2H5 of lever 2M drops to the low part of cam 203 and a character bar 223 selected by an alignment of code bars I394 to I39-5 is allowed to drop into either wide notches 226 or narrow notches 221 of code bars 2Iil to 2iI-l. Now as cam 2B2 releases bail 2H6, code bars 2II-I to 2II-l which present a narrow notch 221 to a selected character bar 223 will be held to the right in a marking position. However, those character bars which present a wide notch 22$ to the selected character bar 223 will be moved to the left or spacing position by springs 2I2. Now according to the operation of code bars 2II-l to 2II-'I, transfer levers 23I code bars I394 8s which are pivoted at 232 will be set since their depending arms 233 rest in projections 234 carried by the code bars.

Pivotally carried on rod 236 is a transfer bail 23'I which is spring urged to the right as viewed in Fig. 13 by sprin I 38 and carries at its lower end a cross rod 239. On cross rod 239 are mounted selector swords ZAI-I to 2 II-1 and two idle signal swords 2&2, 263. Transfer bail 231 includes a follower arm 2% which rides upon cam 2156 mounted on cam sleeve I of shaft I08. lhus, as the high part of cam 246 engages follower arm 2%, transfer bail 23'! is rocked back and forth and swords 24I-I to Z II-I acquire a selective setting from transfer levers 23I in conventional telegraph fashion. Swords 24I-I to Z II-l will now engage either surface 24'! or 248 of latching levers 2494 to 269-1 which are pivoted at 250. Mounted on rod 260 are a pair of lock bails 252, 253 having respective follower arms 254, 255 for engaging respective cams 251, 258. Locking bails 252, 253 are provided with the usual blades 259 which may engage either side of a projection ZEI formed on latching levers 2494 to Hill-l. When the high part of cam 258 engages follower 256, bail 253 frees latching levers Z IQ-I to 229-3 and an idle signal latching lever 21!! for operation. When the high part of cam 25? engages follower arm 254 of bail 252, latching levers itl to 259-? and an idle signal latching lever 285 are freed for operations. When the latching levers are freed for operation as just described, they assume the position of their associated swords 24I-I to Z II-l and accordingly their shoulders 259 block or unblock associated gooseneck transmitting levers 261-I to ZIiI-I which are mounted on rod 262. Thus, transmitting levers 2I to ZGI-I may either close transmitting contact pairs 2634 to 263-! and send a marking signal or allow the contact pairs to remain open and send a spacing signal when operated by their respective cams 264-I to 364-1. In a like manner, idle signal latching levers 210, 265, respectively, control the operation of idle transmitting levers 26355, 261 which are respectively operated by cams 268, 269. Transmitting lever 26% is adapted to send a marking impulse for the second element of the code and transmitting lever 28? is adapted to send marking impulses for the fifth and seventh elements of the code. However, it should be pointed out that idle signal latching levers 276, 265 are differently shaped and are respectively provided with projections 21H 212 which block all transmitting levers ZGI-I to 25k! from operation when the idle signal is transmitted as will be later described. This is accomplished as projections 2', 272 are moved'to a position to block the depending arms 2% oi the transmitting levers 26I-I to 26 i i.

The mechanisms involved in the automatic transmission of idle signals will now be described, with particular reference to Fig. 10. Mounted on rod I68 is a large U-shaped locking bail Z'I'I. Pivotally carried at 2'I8 by bail 211 is a follower lever 279 which rides upon cam 204.

ttached to follower 21s by means of pivot screw 232 is a link bar 283 which is slotted at its opposite end as indicated by numeral 28 to receive bolt 286 carried by a follower arm 28'I which is pivoted at 238 and rides upon cam 239. When the high part of cam 2% presents itself to follower H9 and the apex of cam 289 presents itself to follower 28?, link bar 283 is shifted to the left as shown in Fig. 10. When this occurs, lock- 9 ing blade 290 of bail 211 is freed from projection 29! of an idle signal control lever 292 which is pivoted at 293. However, if follower 219 is on the high part of earn 294 and follower 281 is on the low part of cam 289, follower 281 does not exert the additional motion which is necessary to shift link 283 far enough to the left to free the idle signal lever 292. By the same token, when follower 219 is on the low part of cam 204 and the follower 281 rides the apex of cam 289, again insufiicient motion is imparted to link bar 283 to free the idle signal lever 292. In other words, the sum of the motions produced by the high part of cam 204 and the apex of cam 289 is necessaiy to shift link bar 283 sufficiently to free idle signal lever 292.

Also pivoted at 293 is a divide pawl 294 which rides upon the cam It is so termed because operation of divide pawl 294 determines whether.

an idle or a message signal will be transmitted. In the position shown in the drawings, idle lever 292 is locked in its message or line position by blade 290 of bail 211. Also, divide pawl 294 is shown latched up on shoulder 296 of a latching lever 291 which is pivoted at 298 and urged in a clockwise direction by spring 299. A spring 30! interconnects divide pawl 294 and idle signal lever 292 while a lighter spring 302 tends to urge idle signal lever 292 counterclockwise. Now in each revolution of cam 29!, the apex of this cam operates divide pawl 294 to latch it up on latching lever 291. Also in each revolution of continuously rotating cam sleeve I95 the cam 245 operates transfer bail 231, and near the end of its stroke, after a selection has been transferred, a portion of the bail 280 strikes latch 291 and thereby releases divide pawl 294.

With reference now to the timing diagram (Fig. 15) a resume of the various operations will be given and the automatic insertion of idle signals will be explained. Five unit start-stop signals are received by selector magnet I23, as sleeve I2! is rotated. Approximately during receipt of the fifth impulse by selector magnet I23, cam I59 functions to release sleeve I4I Now, assume message signals are being transmitted, cam I98 mounted on sleeve I95 carried by seven unit shaft I08 will function to release sleeve I42 in conjunction with cam I12 of sleeve I4! in a manner explained in an earlier portion of the specification. It should be remembered that sleeve I95 is a continuously rotating sleeve, while sleeve I42 is a start-stop sleeve. Therefore, sleeve I95 is continuously gaining on sleeve I42.

Now as sleeve I42 is released, cam 203 operates stripper bail 2I8 and all character bars 223 are moved downwardly. Cam 202 now functions to move all code bars 2! I-! to 2II-1 to the right as described. A selected character bar 223 is operated, as the low part of cam 203 is presented to lever 2I4 and swords 24I-I to 24I-1 are set in their selected positions. Cams 289 and 204 combine to unlock idle signal lever 292 by operation of bail 211. Directly after cam 289 operates, cam 246 operates to transfer a new setting to swords 24I-I to 24I-1 by operating bail 231. Cams 251, 258 function successively to enable latching levers to acquire the new setting as bails 25-2, 253 are operated. This new setting is transmitted immediately thereafter as shown in the timing chart. Prior to the operation of bail 231, divide pawl 294 is latched up on latch 291 by operation of cam 29$ and is again tripped by bail 231 near the end of its stroke so that it rides again on the low part of cam 20!. Now as long as cam 246 of the seven unit sleeve I95 is operating later than cam 20! of start-stop sleeve I42, idle signal lever 292 will be retained in its live or message signal position during a transfer since with divide pawl 294 latched up on latch 291, spring 38! is distended and tends to pivot idle signal lever 292 clockwise. It is assumed in the present description that sleeve I95 and sleeve I42 are moving towards the left in the timing diagram and that the apex of cam 289 is at this time in line with the high part of cam 284. After a series of cycles the apex of cam 289 will be operatin in step with the low part of earn 294 and obviously bail 211 cannot unlock idle signal lever 292 at this time. Now as cam 289 continues to gain on cam 204, a point will be reached where the apex of cam 289 will again function in step with the high part of cam 204. This is an indication it is now time to insert an idle signal which must be inserted without losing a signal stored on transfer levers 23!. In other words, transfer of the stored signal must be delayed as will hereafter appear while an idle signal is transmitted and such an operation must be accomplished without loss of any message signals.

When seven unit sleeve I95 has gained on sleeve I 42 to the point where the apex of cam 289 again operates in conjunction with the high part of cam 284 to unlock idle signal lever 292, idle signal lever will now be moved to its idle position by spring 38!. Now as the transfer is made by bail 231, idle signal swords 242, 243 will be set in their idle positions. Ball 291 will again attempt to trip latch 291 at the end of its stroke but it will be ineffective since latch 291 will still be tripped from the previous cycle. These just described operations were made possible since divide pawl 294 is now operated at this point after the transfer has been made by bail 291 and after latch 29'! was ineffectually operated.

While message signals were being transmitted, cams I98 and I12 were effective to release sleeve I4! as explained. However, the release of sleeve I42 is now delayed as the idle signal is transmitted. The combined action of cams I12 and I8! of sleeve Id! will now be necessary to release sleeve I42. When idle signal sword 242 moves to its idle position, projections SI! of idle signal latching levers 219, 265 move into the path of projection 3I2 of lever I94 so that cam follower projection I91 of lever I94 cannot move to the low part of cam I98, and, therefore, link bar I92 cannot function to release cam sleeve I42 in conjunction with cam I12. In other words, sleeve I42 cannot be released until cam I operates after cam I12. During this time sleeve I 95 makes a further gain on sleeve I42 due to the delay in releasing sleeve I42. At this time the idle signal is being transmitted by idle transmitting levers 288, 291, while transmitting levers 2EI-I to 28 I-1' are blocked by projections 21!, 212 of latching levers 218, 265. Now, while the idle signal is being transmitted, cam 205 will function to reset divide pawl 294. lhe apex of cam 289 will again be in step with a high part of cam 204 so that before cam 2'48 operates to make the signal transfer, divide pawl 294 by means of spring 299 will move idle signal lever 292 to its live or message position. As the idle signal transfer is made by operation of cam 24a and bail 231, the signal which was delayed will not now be transferred. It will be noted that this is accomplished approximately in the latter half of the transmission of the sixth element of the idle signal. It will be further noted that cams 258, 25! function immediately afterward to operate bails 252, 253 and permit transmitting levers 264-! to 24l-l to acquire the delayed massage code combination and now transmit the delayed signal; During this interval when the above transfer was made, the idle signal swords 242, 243 were moved to their idle position and levers 2'18, 265 were accordingly operated so that projections 3!! of levers 218, 265 no longer block lever 494 from operation. However, now the high part of cam !98 holds the follower projection l9? of lever I94 so that the sleeve !42 cannot be released by the combined action of cams H2 and {38. However, immediately thereafter the low part of cam !88 will present itself to the follower projection I9? of lever I94 and the sleeve 142 will now again be released in successive cycles by the operation of cams H2 and I98 until it is time to insert another idle signal. It may be further observed that while the release of sleeve !42 was delayed, the operation of cams 283, 282 carried thereby was also delayed so that the setting of the code bars 2! i-l to 2 l l-l and transfer levers 23! in accordance with the next following message signal was also temporarily deferred. Such a transfer now occurs immediately after the preceding delayed signal is transferred to swords 24!-! to 24i-I by operation of cam 243 and hail 23?. Thus, there is no loss of signals when the idle signal is inserted. It will be noted that when cam sleeve !42 is at a complete rest and startstop signals are being converted, a high part of cam 284 presents itself to follower 279 of ball 21'! so that the idle signal lever 292 may be released to its idle position for the transmission of a series of idle signals. Divide pawl !94, of course, will not be operated with cam sleeve !42 idle and it will remain continuously in its tripped position under these conditions.

Having reference now to Figs. 16 and 22, a description will be given of the converter unit which converts seven unit continuous signals into five unit start-stop signals. Numeral 483 represents the base of the unit upon which is suitably mounted end Walls 482, 483. On bearings 464, 486 secured to end walls 482, 463, respectively, is mounted shaft 461?, while on bearings 488, 489 secured to end walls 462, 463, respectively, is mounted shaft 4! Suitably mounted on bearings 4l2, 4!3 is a shaft 4!4 which is coupled in any conventional manner to the motor unit hereinbefore described.

Fast to shaft M4 is a gear 4i6, which is in mesh with a gear 4!! carried about the shaft 4! The relationship of shaft 4!4 to gear 4!? is adjustable by means of a finder arrangement to be later described while the position of a seven unit receiving cam sleeve MS may be adjusted by means of an orienting mechanism now to be described. Gear 4!'! has pivoted thereon at 428 a pawl 4E9 which is normally spring pressed into engagement with a ratchet 42! secured to shaft 4H. Projecting from ratchet 42! is a pin 422 which engages in a'spiral slot 423 carried by a out like member 424 which is suitably secured to cam sleeve 4m. Shaft 4! is slidable in bearings 488, 489 and is normally urged to the left by a lever 426 which is pivoted at 42! and urged counterclockwise by spring 428. At its front end, shaft 4! is engaged by a lever 429 against which bears a cam surface 43! of a pivoted indicator 432 mounted on orienting plate 433. Plate 433 is similar to plate 105 shown in Fig. 4 of United States Patent No. 1,904,164 of Morton et al. dated 12 April 18, 1933. Plate 433 is provided with the usual graduations (not shown) and thus an operation by grasping the handle 434 of pivoted indicator 432 may vary the position of shaft 4! I. This causes pin 422 to move in the spiral slot 423 of member 424 to rotate member 424 and cause the sleeve 4H3 therefore to be adjusted with respectto shaft 45 i or more properly with respect to the incoming signals.

Operation of a finder mechanism associated with this conversion unit will now be described. The finder mechanism. operates in a somewhat similar manner to the finder mechanism described in connection with the motor unit. It will be understood that both the finder mechanisms may not have to be used. The finder mechanism about to be described may find utility if a separate motor were used to drive the seven to five unit code conversion unit, rather than the motor unit previously described. As described above, pawl 4H! carried on gear 4!! is in engagement with ratchet 42! and thereby drives ratchet 42!. Operable by a finder magnet 436 is an armature 43'! having a follower arm 438 and a pawl tripping arm 44!, the armature being pivoted on rod 442. When finder magnet 436 is energized due to failure of the apparatus to be in phase with apparatus at a remote station in response to the receipt of idle signals, the armature 43'! is attracted and when groove 443 of a cam 444 carried on sleeve 445 presents itself to follower arm 438, the follower arm 438 will drop into the groove and the free end of pawl tripping arm 44! will move into the path of pawl 4!!) and cause the pawl to be tripped and engage the next succeeding tooth of the ratchet so that the driving relationship between gear 4! 6 and cam sleeve 4!8 has been altered. This operation is cyclically repeated until the correct phase is established. There are seven teeth on the ratchet 42! which represents the seven code elements of a signaling code combination. Thus, the finder mechanism may be used for phasing the apparatus with respect to incoming signals while the orienting device can be used for adjusting cam sleeve 4% within the individual impulses. Contact pair 448 is operated in a manner similar to contact pair 56 which was described in connection with the finder mechanism included with the motor unit.

Also carried on shaft 4!4 is a gear 45! which is in mesh with a gear 452 carried on shaft 481. For the purpose of the present description shaft 41! may be referred to as the seven unit shaft and shaft 48'! may be considered to be the five unit shaft. Incoming continuous seven unit signals are received by the selector magnet 453 which is part of a single magnet selector 454. As the signals are received the seven swords 456 are set in the usual manner according to the nature of the received impulses by the sequential operation of cams 457-! to 451-! carried by receiving cam sleeve 458. In addition, cam sleeve 458 carries lock cams 459, 43! which respectively operate lock bails 462, 463 during receipt of the seventh and first impulses of a code combination. Bails 462, 463 are both pivoted on the rod 464 and are provided with the usual springs 465 for enabling the bails to follow the periphery of their cams by mean of their respective follower arms 466, 461. Each ball is provided with a locking blade 468 designed to engage either side of projections 469 carried by locking levers 4l!-! to 4'!!-'!. Bail 462 controls locking levers 4'! to 4'! !3 and bail 463 controls locking levers 4'H-4 to 4'!!-'!.

The

pointed end of swords 455 may engage either surface 412 or 413 of associated lock levers 411-1 to 411-1 and accordingly operate the lock levers about the pivot 414 when the locking bails 452, 463 are operated. The lower ends of levers 411-1 to 411-1 are engaged in notches 415 of associated notched seven unit code bars 411-1 to 411-1. Underlying the seven unit code bars 411-1 to 411-1 and the five unit code bars 418-1 to 418- are a series of character bars which are pivoted on rod 421 and urged upwardly by individual springs 481.

Carried on sleeve 418 is a cam 482 which in each cycle of operations rocks the follower 483 about its pivot 484. Follower 458 is urged clockwise by means of a spring 481 and is pivotally connected at 488 with stripper bail 489. For maintaining parallelism, bail 489 is pivotally connected at 481 with a lever 482 which is pivoted at 4911. As the high part of cam 4-32 works against follower 483, all character bars 419 are moved downwardly and while they are so held a cam 493 operates a follower 454 about its pivot 495 against the tension of spring 495 to push all code bars 418-! to 418-5 to the left by reason of the engagement of follower 484- with projection 491 of the code bars. Follower 488 now drops off the high part of earn 482 while code bars 413-5 are held to the left and a selected character bar 419 now moves into an alignment of notches in code bars 411-1 to 411-1 and into an alignment of wide notches 498 and narrow notches 458 of code bars 418-1 to 418-5. Now when follower .54 drops to the low part of cam 493, code bars 418-1 to 418-5 having wide notches 488 in engagement with the selected character bar 418 will be allowed to be drawn to the right or spacing position by individual springs 55 1, while those having narrow notches 498 will be retained to the left in marking positions. Pivotally supported at 552 on individual code bars 418-1 to 418-1 are latches 503, which are spring urged to the left by individual springs 594. Formed on latches 55-3 are bifurcations 555 which straddle the lower end of a latching lever 551 which is pivoted at 558. At it upper end, each latching lever 551 is provided with a projection 5138 designed to be engaged at either side by blade 51 I of locking bail 512 which is pivoted on rod 513 and urged counterclockwise by spring 514. Bail 512 includes a follower arm 516 which rides upon cam 511 carried by transmitting sleeve 518 of shaft 451. When bail 512 is operated, latching levers associated with code bars 418-1 to 418-5 set in spacing position will be in the position shown and shoulders 518 of lever 501 will prevent closure of transmitting contact pair 521 by transmitting gooseneck lever 522 when cam sleeve 511 and cams 525-1 to 528-5 are released. On the other hand, upon operation of bail 512, those code bars 418-1 which are in marking position to the left by means of springs 584 will now cause levers 553 to pivot slightly counterclockwise thereby withdrawing shoulder 518 from the path of transmitting gooseneck levers 522 and enable closure of transmitting contact pairs 521-1 to 521-5 when cam sleeve 518 is released for operation. It should be pointed out that as a code bar 418-1, for example, is moved to the left, spring 5134 is placed under tension and tends to draw lever 588 counterclockwise but cannot do so until bail 512 is operated. This makes possible a signal overlap arrangement to,

hold a signal code combination by means of code bars 418-1 to 418-5 until bail 512 is operated.

The means of releasing the transmitting sleeve 518 by operation of clutch 515 will now be described. Carried by sleeve 518 is a release disc 524 which in the rest position of the sleeve, has a high part in engagement with stop arm 525 of the clutch lever 525 which is pivoted at points 521 and urged in a clockwise direction by spring 528. Pivoted at 529 is a follower 531wvhich is urged clockwise by a spring 532 and rides upon a cam 533 carried by sleeve 418 of shaft 411. In the position shown, follower .531 holds a slidable bar 534 to the left. However, when follower 531 is operated by cam 533, a spring 585 pulls bar 534 to the right and a projection 581 formed thereon engages tall 538 of clutch lever 526 to thereby release cam sleeve 515. When an idle signal is received, idle character bar 539 will move into notch 541 of bar 534 to thus prevent the release of cam sleeve 518.

A typical conversion operation by means of the seven to five unit converter will now be briefly described. A seven unit signal code combination is received by selector magnet 453. During receipt of the sixth element of the code, bail 456 operates and code bars 411-1 to 411-8 are set. During the next following first element period of the code, bail 451 operates and code bars 411-4 to 411-1 are set. Immediately thereafter, cam 4-52 and follower 483 function together with earn 498 and follower 484 as explained to enable code bars 418-1 to 418-5 to receive the converted selection. Approximately during the fifth element period of the seven unit code, cam 533 functions to release cam sleeve 518. Immediately thereafter bail 512 operates and frees latching levers 551. The five unit start stop signal is transmitted as cam sleeve 51% is released. It should be mentioned that the usual start-stop transmitting cam 545 is provided on sleeve 518. If an incorrect signal is received by the seven unit selector which is not composed of three marking and four spacing impulses, the five unit start-stop sleeve 518 will be released and all spacing signal will be transmitted as no character bar is selected at this time since all code bars 415-1 to 418-5 will move to their spacing positions. Receipt of an all spacing signal by the five unit receiving station will cause the printing of an error indication character.

What is claimed is:

1. In a telegraph converter apparatus, selector means responsive to the receipt of continuous signal code combinations, including idle signal code combinations, a first series of code bars controlled by said selector means in accordance with the receipt of said signal code combinations by said selector means, a series of character bars individually selectable by said code bars, a second series of code bars less in number than said first series of code bars and controlled by said individual character bars, a series of transmitting means individual to said second series of code bars and controlled thereby, means for cyclically operating said transmitting means to transmit signal code combinations composed of equal length impulses, means to transmit start-stop impulses to accompany each of said code combinations, and means responsive to the receipt of said idle signal code combinations by said selector means for preventing the operation of said cyclically operative means to thereby delete said idle signal code combination.

2. In a telegraph converter apparatus, selector means responsive to the receipt of continuous signal code combinations including idle signal code combinations, a first series of code bars controlled by said selector means in accordance with the receipt of said signal code combinations by said selector means, a series of character bars individually selectable by said code bars, a. second series of code bars less in number than said first series of code bars and controlled by said individual character bars, a series of transmitting means individual to said second series of code bars and controlled thereby for transmitting signal code combinations composed of equal length impulses, means to transmit start-stop impulses to accompany each of said code combinations, means for cyclically operating said transmitting means including a clutch having a clutch operating lever, and means responsive to the receipt of said idle 17 code combination by said selector means for preventing the operation of said clutch lever to thereby delete transmission of the idle signal code combinations.

3. In a telegraph converter apparatus, a single magnet responsive to the receipt of continuous signal code combinations, a first series of code bars, means controlled by said single magnet in accordance with the receipt of said signal code combinations for selectively positioning said first series of code bars, a series of character bars individually selectable by said code bars, a second series of code oars less in number than said first series of code bars, means selectively controlled by said individual character bars for positioning said second series of code bars, a series of transmitting levers, means for transferring a selection from said second series of code bars to said transmitting levers, means associated with said transmitting levers for transmitting signal code combinations composed of equal length impulses, means to transmit a startstop impulse to accompany each of said signal code combinations, and means for preventing the operation of the transmitting means upon reception of a predetermined continuous signal code combination in the magnet.

4. In a telegraph code converter apparatus, a single selector magnet for receiving signal impulses of a first predetermined code, a first series of code bars, means actuated by the selector magnet for permutatively positioning said code bars in accordance with the reception of signal code impulses, a second series of code bars, mechanically operated means for transferring the permutated setting of the first series of code bars to the second series of code bars, transmitting means for transmitting signal impulses in accordance with the setting of the second series of code bars, and a mechanical lock means operated by a predetermined permutative setting of the first series of code bars for preventing the operation of the transmitting means.

5. In a telegraph code converter, selector means for receiving signal impulses of a first predetermined signal code, means positioned by said selector means in accordance with said incoming signal impulses, a series of code bars, mechanically operated means for transferring the setting of the positioned means to the code bars whereby the code bars are set in a permutation different from the setting of the positioned means, a series of transmitting contacts, means to actuate the transmitting contacts in accordance with the setting of the code bars for transmitting signal impulses in a second predetermined code, and means responsive to a predetermined setting of the positioned means for preventing the operation of the transmitting contacts.

' 6. In a telegraph code converter, a first set of code bars, a selector magnet, a continually rotatable first shaft, cams mounted on the first shaft, means controlled by the cams and the selector magnet for permutatively positioning the first set of code bars, a second set of code bars, an intermittently operated second shaft, a group of second cams mounted on the second shaft, means for transferring the setting of the first set of code bars to the second set of code bars in a different permutation, a clutch associated with the second shaft, a mechanism controlled by the first continually rotating shaft for cyclically releasing the clutch to operate the second intermittently rotatable shaft, and means controlled by the rotation of the group of second cams and the setting of the second set of code bars for transmitting signal impulses in accordance with the permutative setting of the second group of code bars.

7. In a telegraph code converter apparatus, a single selector for receiving signal code impulses of a predetermined code, a continually rotative shaft having a plurality of operating cams mounted thereon, a first series of code bars, means cooperating with a portion of said cams and selectively positioned by energization of said selector magnet for positioning said series of code bars in accordance with the received signal impulses, a series of character bars, mechanical means controlled by another of said cams for selectively positioning said character bars in accordance with the selective setting of said first series of code bars, a second series of code bars, means for biasing said second series of code bars in a predetermined direction, mechanical means controlled by another of said cams for moving said second series of code bars against said biasing means into a position to be selectively engaged by said character bars, said last mentioned cam means further functioning to release said second series of code bars whereby certain of said second series of code bars are permutatively retained by said selected character bars in a permutation different from that of the first series of code bars, transmitting means adapted to transmit signal impulses in accordance with the permutative setting of the second series of code bars, and mechanical means controlled by another of said cams for initiating operation of said transmitting means.

8. In a telegraph code converter, a first set of code bars, a selector magnet, a rotatably mounted shaft, a plurality of cams mounted on the shaft, means adapted to be controlled by a portion of the cams and the selector magnet for permutatively positioning the first set of code bars, a second set of code bars, a series of charac ter bars, means for urging the character bars into engagement with both sets of code bars, a first bail controlled by one of said cams for holding the character bars against the effect of the urging means, means for urging the second set of code bars in a predetermined direction, a second bail controlled by another of said cams for holding said second code bars against the eifect of the urging means, transmitting means adapted to be controlled by the second set of code bars, a clutch associated with the transmitting means for holding said transmitting means from operation, a clutch release mechanism controlled by another of said cams, and means for continuously rotating said cam shaft whereby said first code bars are permutatively positioned by the joint action of the cams associated therewith and the energization of the selector magnet in accordance with incoming signals, said cams further functioning tative setting of the second set of code bars. to release the bail associated with the character MARTHA W. C. POTTS, bars to permit the first code bars to select one of Emecutria: under the last will and testament of the character bars, then releasing the bail asso- Louis M. Potts, deceased.

ciated with the second code bars to permit the 5 References Cited in the me of this patent second code bars to be permutatively positioned in accordance with the particular character bar UNITED STATES PATENTS selected, and finally actuating said clutch release Number 7 Name Date mechanism to cause the transmitting means to 2,273,776 Zurek Feb. 1'7, 1942 transmit a signal in accordance with the permu- 10 2,309,222 Spencer Jan. 26, 1943 

